Validate email addresses and check deliverability
| Name | Required | Description | Default |
|---|---|---|---|
| emails | Yes | Array of email addresses to validate | |
| check_mx | No | Check MX records for domain | |
| check_smtp | No | Perform SMTP validation |
Changes observed during successful MCP inspections. Dates show when Glama detected each change.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries full burden but only says 'validate' and 'check deliverability'. It does not disclose that this may involve network calls, MX/SMTP checks, potential side effects, rate limits, or what the return value contains. The behavior is largely opaque.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is a single concise sentence, front-loaded with the verb 'Validate'. It has zero waste and every word contributes to conveying the core purpose. This is appropriately sized for a simple tool.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
The tool has no output schema and no annotations. The description only states the basic action, omitting return format, behavioral nuances, and usage context. Given the complexity of email validation (MX/SMTP checks, deliverability semantics), the description is not complete enough for an agent to fully understand the tool's behavior.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema description coverage is 100%, so the baseline is 3. The description itself adds no extra parameter meaning beyond the schema's existing descriptions of 'emails', 'check_mx', and 'check_smtp'. No interpretation or additional context is given.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description clearly states the tool validates email addresses and checks deliverability, which is a specific verb and resource. It does not explicitly distinguish from sibling tools like check_email_config or test_email_config, but the focus on email addresses rather than configuration makes it clear enough.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
No guidance is provided on when to use this tool versus alternatives. There is no mention of prerequisites, exclusions, or preferred scenarios, leaving the agent to infer usage from the name and schema alone.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
